The purpose of this study is to compare the tumoricidal effect of the CO2 laser to that of cryogenic destruction in an animal model. In particular, treatment efficacy as measured by survival and recurrence rates as well as oncogenic potential of residual tumor will be determined. Tissues containing a standard epitheloid tumor will be treated by both modalities and then subjected to histologic and histochemical analysis and cross-implantation virulence studies. The determination of the relative efficacy of these treatment modalities is the ultimate objective.